Auryon Laser in Treating Symptomatic Infrainguinal Arterial Disease: 1-Year Outcome

Abstract

Background. The Auryon 355-nm laser atherectomy system (AngioDynamics, Inc) showed a low rate of target-lesion revascularization (TLR) at 6-month follow-up in the EX-PAD-03 investigational device exemption study and the Auryon single-center experience (SCE) in treating infrainguinal arteries. In this study, we present the 1-year outcomes of the Auryon SCE study on TLR in all comers at a single center. Methods. The Auryon SCE was a retrospective study that evaluated the outcomes of all comers treated with the Auryon laser for infrainguinal arterial disease. There was no TLR seen at 6-month follow-up. We present the TLR rate at 1 year in the same cohort of patients. TLR rates were obtained from medical record review of patients enrolled in the study who had completed office visit follow-up at 1 year. Secondary endpoints included unplanned major amputation and total mortality. Kaplan-Meier survival analysis was performed to estimate the freedom from TLR rate following index procedure. Statistical differences were analyzed for ankle-brachial index (ABI) between baseline and 1 year. Results. A total of 56 patients (65 procedures, 70 lesions) were enrolled. The mean age was 70.9 ± 10 years, with 66.1% males, 48.2% diabetics, and 25% demonstrating limb ischemia. Of the 70 lesions, 31.4% had severe calcification, 38.6% were chronic total occlusions, and 48.6% were de novo disease (in-stent restenosis, 29.6%). Stenting was performed in 24/70 lesions (34.3%), with 11/70 (15.7%) bailout procedures. Embolic filters were used in 26/65 procedures (40%). The majority of treated lesions were femoropopliteal (90.0%); of all procedures, 29.2% had 2 or more prior interventions. Drug-coated balloon usage was 47.1% Lutonix (BD/Bard), 27.1% In.Pact (Boston Scientific), and 1.4% both in all lesions treated. Distal embolization occurred in 1/65 procedures (1.5%). At 1 year, mortality occurred in 3/56 patients (5.4%). Of 65 limbs treated, 2 (3.1%) had major amputation at 1 year. The probability of freedom from TLR was 83.7%. Conclusion. In a real-world cohort of patient with complex disease, the Auryon laser had excellent freedom from TLR at 1 year.

Keywords: Auryon laser, femoropopliteal artery, outcome, retrospective, target-lesion revascularization

The Auryon laser atherectomy system (AngioDynamics, Inc) has a long wavelength (355 nm), leading to low penetration depth of its thermal energy^1,2 and a low rate of deep dissections as demonstrated by intravascular ultrasound.³ Adventitial tears correlate with a higher rate of restenosis and target-lesion revascularization (TLR).⁴ Early data demonstrated an excellent procedural and short-term outcome with the Auryon laser system.^5-7 We present the 1-year follow-up data of the Auryon single-center experience (SCE) retrospective study of patients treated for infrainguinal symptomatic arterial disease with the Auryon laser atherectomy system.

Methods

Consecutive patients treated with the Auryon laser system between September 2017 and March 2021 were retrospectively reviewed from a single center and single operator (NWS). The study was approved by WIRB, a central institutional review board. Demographic, procedural, angiographic, and 6-month outcomes data have been previously published.⁷ In this follow-up report, we present the 1-year TLR, mortality, and amputation outcomes. Data were extracted from patients’ medical records for all patients who had a 1-year follow-up visit. The study’s primary endpoint was the assessment of freedom from TLR at 1 year.

This study included 56 patients, of which 9 had procedures on both legs and 5 patients had 2 lesions on 1 leg. TLR rates were calculated by accumulating the TLRs through the period from baseline out of the number of procedures at risk at the beginning of the period following the index procedure. Statistical differences were also analyzed for ankle-brachial index (ABI) between baseline and 1 year. Analyses was performed per patient, per procedure, and per lesion. Kaplan-Meier survival analysis was performed to estimate the freedom from TLR rate following the index procedure. Statistical significance was determined by a P-value <.05. Analysis was performed with Minitab 2020 and Cytel 11 software.

Results

A total of 56 patients (65 procedures, 70 lesions) were enrolled. Detailed data on the patient demographics, procedural characteristics, and angiographic variables have been previously published.⁷ The mean age was 70.9 ± 10 years, with 66.1% males, 48.2% diabetics, and 25% with limb ischemia. Of the 70 lesions, 31.4% had severe calcification, 38.6% were chronic total occlusions, and 48.6% were de novo disease (in-stent restenosis, 29.6%). Stenting was performed in 24/70 lesions (34.3%), with 11/70 (15.7%) bailout procedures. Embolic filters were used in 26/65 (40%) procedures. The ­majority of treated lesions were femoropopliteal (90.0%) and 29.2% of all procedures had 2 or more prior interventions. Drug-coated balloon usage was 47.1% Lutonix (BD/Bard), 27.1% In.Pact (Boston Scientific), and 1.4% both in all lesions treated. Distal embolization occurred in 1/65 procedures (1.5%). This patient had a Wirion filter (Cardiovascular Systems, Inc). All patients were able to be tracked through medical records for 1 year. Of 65 limbs treated, 2 (3.1%) had major amputations at 1 year. At 1 year, mortality occurred in 3/56 patients (5.4%). The Kaplan-Meier censored all-cause mortality. The probability of freedom from TLR was 83.7% following the index procedure (Figure 1).

Discussion

The Auryon laser has shown excellent 6-month outcomes with very low TLR rates (3.3% in the EX-PAD-03 trial and 4.4% in the Auryon SCE).^6,7 The 1-year follow-up data in the Auryon SCE continued to show excellent freedom from TLR in a complex subset of patients with high rate of chronic total occlusions and severe calcium. The Auryon laser has been shown to have a low rate of deep dissections.³ Adventitial dissections are a predictor for TLR and restenosis.⁴ This may partially explain the overall low TLR rate seen at 1 year. Another explanation, however, could be the higher use of drug-coated balloon in the Auryon SCE or both the combination of adventitial sparing and drug-coated balloon use. The added value of vessel preparation with the Auryon laser over drug-coated balloon on patency and TLR remains unknown and needs to be tested in a randomized trial. In the Auryon SCE, the dissection rates were low. Bailout stenting was mostly due to residual narrowing >30% (9/11 lesions) and, to a lesser extent, flow-limiting dissections D or higher (2/11 lesions). This could be due to the laser being a soft debulking device (reducing lesion severity by about 30%-40%) in contrast with other atherectomy devices, such as the Jetstream (Boston Scientific) or Hawk devices (Medtronic).⁸ The advantage of debulking, including with the Auryon laser, is in the reduction of bailout stenting. The Auryon device has been shown to have a low bailout stenting rate of 0.9% in the EX-PAD-03 investigational device exemption study. We suspect our bailout stenting rate was higher because of the significantly more complex disease included in this real-world consecutive cohort of patients. Mortality and amputation rates were low in our study, considering that 25% of patients had chronic limb-threatening ischemia. The instances of mortality and amputation seen in our patients were determined to be unrelated to the device or the procedure.

Study limitations. The study is retrospective; therefore, potential bias in patient selection could have occurred, although the lesion complexity included reduces this possibility. Prospective long-term data are needed to verify these findings and likely will soon be available from the Pathfinder I registry (ClinicalTrials.gov identifier: NCT04229563), a prospective, real-world study of the Auryon laser in femoropopliteal disease. Finally, randomized trials are needed to determine whether the Auryon laser is superior to angioplasty or stenting with or without antiproliferative therapy in treating femoropopliteal arterial disease.

Affiliations and Disclosures

From ¹the Midwest Cardiovascular Research Foundation, Davenport, Iowa; and ²Angiodynamcis, Inc, Latham, New York.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Shammas receives educational and research grants from Angiodynamics, Boston Scientific, Bard/BD, VentureMed Group, and Philips; speakers’ bureau for Janssen, Eli Lilly, Esperion, Boehringer Ingelheim, and Kiniksa. Dr Shankarraman is an employee of Angiodynamics. The remaining authors report no conflicts of interest regarding the content herein.

Manuscript accepted June 1, 2022.

Address for correspondence: Nicolas W. Shammas, MD, MS, FACC, Research Director, Midwest Cardiovascular Research Foundation, 630 East 4th Street, Davenport, IA 52803. Email: shammas@mchsi.com

References

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